Apparatus for the fluid treatment of yarn



Jan. 26, 1954 H. KARLEN ET AL APPARATUS FOR THE FLUID TREATMENT OF YARN 4 SheeJcS-Sheet l Filed Jan. 19, 1950 Jan. 26, 1954 H. KARLEN ET AL APPARATUS FOR THE FLUID TREATMENT OF YARN SN rfa w a ma m wam e 3 m .Mc E s A n m m @G S A E 4 H@ Filed Jan. 19, 1950 Jan. 26, 1954 H. KARLEN ET AL APPARATUS FOR THE FLUID TREATMENT OF YARN Filed Jan. 19 1950 N0 @sd m 3 A V A.' v C f r imm JWM. fw wkn L .mw

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APPARATUS FOR THE FLUID TREATMENT oF YARN 4 Sheets-Sheet 4 l n? I l @T I I l gli ,i Jnventors #5e/MNM fmzf/v Filed Jan. 19, 1950 attorney Patented Jan. 26, 1954 APPARATUS FOR TILE` FLUID TREATMENT IOF YARN Hermann Karlen,

Switzerland, France, assignors to and Eugne Colomhu,

Societe de la Viscose Suisse,

Emmenbrucke, near Lucerne,

Paris,

Emmenbrucke, near Lucerne, Switzerland, a

Swiss company Application January 19, 1950, Serial No. 139,434

Claims priority, application Great Britain January 26, 1949 Claims.

This invention relates to the production of artificial filaments, and more particularly to the production of iilaments of regenerated cellulose from viscose solution.

Many processes are known wherein articial filaments are produced by the successive steps of coagulation, setting, washing and bleaching in different baths, and are continuously dried as they leave the inal processing bath.

In carrying out this process filaments of any normal count, or preferably a sheet of filaments in parallel alignment, so-called warp formation," is passed through a series of suitable treatment baths.

Various more or less detailed proposals have hitherto been made in connection with processes of this type. Thus, for example, British patent speoication No. 16,495/67 describes a process in which the ilaments, in Warp formation, and under little tension, are carried on rising belts which are sprinkled in the vicinity of their upper ends with the treatment liquids which flow by gravity down the belts counter-current to the travel of the filaments. The filaments are then dried on a heated drum and the dried la- .i

ments are wound or Wound and twisted.

In British patent specication No. 211,446, a modified method is described in which filaments in Warp formation are guided through a succession of treatment baths, surplus treatment liquid being extracted from the filaments between the successive baths, and are continuously dried on an assembly of closely disposed heated rollers and thereafter Wound. This technique has been applied to the production of artificial staple liber and British patent specification No. 311,399 describes a variation of this process by which the time required for travelling through each treatment bath is reduced to 5 to 10 seconds. In this process bundles of fibers having a total count, for example, of 60,000 to 89,000, are immersed in the successive baths with the aid of guides, e. g. rollers, and are squeezed free of surplus liquid after each bath by passage through squeezing rollers, the bundles of ibers being subjected to little or no stretching tension. British patent specification No. 356,975 describes a further Variation of this method applied to the treatment of llaments in which the guides are in the form of hooks which hold the filaments immersed in the treatment liquids but do not stretch them. The drying of the sheet of iilaments is effected, for example, on a heated cylinder and the lilaments are then Wound on a single reel or on separate bobbins.

Other methods which may be mentioned include that of French Patent No. 733,717 in which large bundles of filaments are immersed in treatment baths and guided by means of annular grooves in guide drums, the filaments being sprayed on leaving such bath; that of French Patent No. 744,480 in which the drying is effected with the filaments travelling through individual vertical tubes, the only tension on the filaments being that due to their Weight; that of German Patent No. 733,792 in which a continuous sliver of bers is treated almost on the surface of the baths, the sliver being guided by means of noncircular reels dipping slightly in the baths and producing a vibration in the sliver whereby it is opened out to facilitate the liquid treatment; and that of Belgian Patent No. 472,734 in which a plurality of filaments in Warp-formation are guided through a number of treating baths on the surface of the liquid, the guiding being ei- ,fected by the provision of combs.

None of the foregoing methods is wholly satisfactory and the present invention is concerned With an improved method for the continuous treatment of filaments, and particularly viscose filaments which results in filaments of uniform quality and excellent semi-metric properties and Y which presents advantages in regard to the ease of control of the process generally and the ease with which noxious gases which may be formed in the treatments may be extracted and recovered.

According to the present invention a process for the production or treatment of artificial filaments, and more particularly for the production of iilaments by the viscose process or for the treatment of such lilaments, which comprises passing a plurality of such lilaments continuously With the production and While in Warp for-mation continuously through a series of liquid treatment operations to a nal drying operation, the iilaments being passed through squeezing rollers at the end of each liquid treatment operation and during each liquid treatment operation following a free path out of Ycontact with rollers or other mechanical devices and out of Contact with any substantial body of liquid, whereby any frictional drag on the :filaments is substantially avoided and the tension on the filaments is held at a low yconstant value..

In the preferred forms of the invention the liquid treatments are effected by spraying the treating liquid on to the laments. Preferably the laments are caused to travel in individual shallow troughs which rise in the direction of filaments and preferably the apthe sheet of filaments travel of the paratus is so set up that suffers no sudden change in direction during its travel through the treatment liouids. Further, it should in all cases be so arranged that the tension on the filaments is as lovv as conveniently possible during the various treatments.

In the drying operation it is preferable that the filaments travel over spaced guides such that by far the greater part of the travel of the filaments during this operation is in a substantially vertical direction.

Preferred embodiments of this invention will now be described with reference to the accompanying drawings but it will be understood that these embodiments do not constitute any limitation of the invention and also that, though the description relates to the continuous production and treatment of viscose filaments, the apparatus described may be applied to the production and treatment of other articial filaments and yarns.

Referring to the accompanying drawings:

Fig. 1 is a diagrammatic representation of an apparatus embodying the invention;

Figs. 2A and 2B placed side by side are vertical longitudinal sectional views of the apparatus;

Figs. 3A and 3B placed side by side are a plan view of the apparatus, Fig. 3A being partial section on line SA--SA of Fig. 2A;

Fig. 4 is an enlarged section taken on the line i-i of Fig. 2A illustrating a detail of the apparatus;

Fig. 5 is a diagrammatic representation of the drying apparatus;

Fig. 6 is a detail of a drying roller;

Fig. 7 is a longitudinal section through a modined form of trough;

Fig. 8 is a longitudinal section taken on the line 8-3 of Fig. '7;

Fig. 9 is a plan View of a form of trough;

Figl is a section taken on the line l-IU of Fig. 9`;

Fig. '11 shows in longitudinal section of another form of trough;

Fig. 12 is a side elevation of still another form of trough; and

Fig. 13 is a plan view of the trough of Fig. 12.

Referring to Figs. 1, 2A, 2B, 3A and 3B, the spinning solution, which in this case is viscose, is fed in a well known manner through a series of spinnerets l, which dip into a coagulating bath 2. While still in the neighborhood of the suinnerets, the groups of superciallv coagulated filaments 3 enter fairly long tubes ll, carrying alone. the coagulating liouid in their movement, in the manner described in U. S. Patent No. 2.511.699 while the other extremities of the tubes partly emerge from the bath 2. The sheet formed of the groups of filaments 3 is freed from some of the bath licuid adhering thereto by passing over a smooth scraper blade 5, for example of glass, and is then taken un by a series of three rollers 8, 'l and 8 which determine by their speed (which is the Same for all three) the linear speed of the sheet leaving the coagulating bath. Excess bath liouid carried along is expelled by a pressure roller 9 bearing against the roller 'i and loaded by a spring 9a. The sheet then enters a bath l0 containing hot water or dilute sulphuric acid, at a temperature of from 50 C. to 95 C., in which the filaments are stretched, the stretching being achieved by providing delivery rollers il, l2, I3 rotating at equal speeds but faster than the rollers 6, 1 and 8. The degree of stretching may beg for example,

20% to 120% according to the yarn to be produced. The sheet is held immersed in the hot bath i0 by rods I4, l5, for example of smooth glass, or by rollers of small diameter. A pressure `roller I6 bearing against the roller i2 and loaded by a spring iEcL removes the excess liquid entrained by the laments.

From the time when the sheet 3 leaves the roller i3 until it emerges from the final treatment bath, it remains plane and horizontal or slightly inclined. This feature, which results in the minimum mechanical interference with the laments, is one of the important features of the invention. Continuing its forward movement, the sheet passes from the roller I3 and enters a rst washing stage constituted by a series of parallel open troughs, a partial sectional view of which is shown in Fig. 4, there being one trough for each bundle or for each filament. This arrangement may be constituted by a corrugated metal sheet il, the corrugations of which lie fairly close together and which rises slightly, but a plate suitably grooved by machining, molding or other means, can also be used. The sheet l1 should not be fragile, and should be smooth and acid-proof. A sprinkler H3Y (comprising a plurality of nozzles) feeds washing liquid, which may be either cold or hot according to requirements, from a vat (not shown) below the corrugated sheet I l into each of the troughs I1 of said sheet (see Figs. 2A, 3A, and 4) and onto the filaments passing therethrough, the filaments carrying the liquid with them while undergoing the washing. Convenientlyr the direction of the jets of liquid should conform to the travel of the filaments and the arrangement may be such that some pulsating motion is imparted to the filaments to facilitate the treatment.

Upon leaving the troughs l1', the surplus liquid is expressed from the filaments and returned to the vat (not shown) by squeeze rollers comprising a roller l 9 of rubber or other elastic material and a hard roller 20. The roller 2t is strongly pressed against the roller 9B by springs Ita.

One important feature of the invention resides in the fact that the speed of the snueece rollers i9, 20 is about 2% to 10% less than the speed of the roller I3. Well known means, not shown such for example as variable speed gears having a common drive, precision gears or difeentials may be employed for this purpose and bv means of this arrangement the tension on the .lements is reduced. In this wav a predetermined constant low tension is imparted to the filaments. This cle-tensioning considerahlv facilitates wa shing, even in the case of large bundles comprising several thousand laments.

The filaments then undergo a fw'ther washing under the same conditions in a stage 2l identical to the first etage and are sprayed by a sprinller 20A. identical with the sprin"ler I8. Further identical washing operations can be successively applied. To complete the de-tensioning of the filaments, the speed of the squeef'e roller Zia at the downstream end of the stage 2l can be further reduced, for example, up to a maximum of 1%.

Following the last washing operation further purifying treatments can be carried out under exactly the same conditions, with or without further de-tensioning, for example, desulphurization in the stage 22, followed by rinsing in the stage 23, followed by bleaching and another rinsing operation in stage 2S (Fig. l).

Upon leaving the last trough in which the purifying treatment is applied, the laments are lubricated by the application of a solution of a suitable substance, for example, a substance containing active anions, such as the sodium sulphate of oleic alcohol, or a substance containing active cations, suc as cetylpyridinium bromide, for example in a 5% aqueous solution at 56 C. The filaments taken up by the squeeze rollers 24, 25 loaded by the springs un ergoes, in a stage 25 similar to the st es 5l, 2i and 22,. a sprinkling' treatment by means of parallel nozzles 2l similar to the devices i8 and Etc, the bath liquid thus supplied being carried along by the larnents in the individual troughs. Following this treatment, the surplus liquid is expressed from the filament by means of the rollers Z3, 2s loaded by the springs 29a, and then again by the squeeze rollers Se, 3i loaded by the spring Sie.

It will be noted that the laments extend absolutely straight in their passage from the roller i3 to the final squeeze rollers 3%, 3i. The bath liquid can be recovered if necessary and re-circulated by well-lrnown means. In the washing phase, fresh soft water can be used for the last washing operation `and the used water can be returned into the preceding stage, and so on. Further suitable treatments can also be applied after the oiling and before the nal drying, by means of stages similar to those employed in the preceding treatments. Such further treatments include dyeing or sizing.

The final extraction of liquid by means of the squeeze rollers 28, 2S and 3i should be arranged to produce filaments containing from 160% to 200% water on a dry cellulose basis, which can be dried in the drying apparatus hereinafter described. Using a single squeeze roller, i. e. omitting squeeze rollers 23, Z9 or squeeze. rollers 3E, 3l there remains about 50% more of water to be evaporated and this is usually excessive for economical drying. It is useful to irnpart a certain tension to the nlaments while they are being lubricated and the speed of the squeeze rollers 28, i9 and E2, 3i can be so regulated that the nal speed of the filaments is almost equal to its speed at the rollers i i, E2, i3 or even up to 5% higher.

The lila-ments leaving the squeeze rollers 3B, 3l pass through a comb 32 or through a series of desired g "de means, the bundles being individually guided in both case The bundles then converge on a comb similar to the guide 32, the sheet of filament remaining flat, the bundles however being close together with a View to a more economic drying. In this connection it should be mentioned that the width of the sheet of filaments to be dried and the humidity thereof are the principal factors in determining the heat requirements during the drying.

The lafnent sheet, reduced for example to a width of from 3G om. to 5G ein (the individual bundles remaining substantially equidistant) passes through a narrow slot Se into a dryer 35, in which it is dried in long, free, flat, parallel guided by guide rollers.

A preferred form or drying apparatus is shown in Fig. 5 where the main part of the travel of the filament sheet is in a vertical direction but it is also possible to arrange for the sheets to be dried in horizontal or inclined paths. lt is preferred that the sheet should have unguided travel through distances not less than 150 cm. It would even be preferable to provide only one guide means at the entrance and another at the outlet end of the dryer, so that the filaments are not touched at -all in the dryer, which thus constitutes a long tunnel, but from the practical standpoint vertical travel is preferred and the construction would then be very high (several dozen meters). A horizontal construction presents the diiiiculty that the individual bundles of the sheet tend to hang, which entails diiiiculties in the uniform distribution of the heat and the possibility of entanglement of the filaments due to the currents of gas arising from the circulation of the drying gas in the dryer. Moreover, the tunnellike construction referred to above entails, due to the great surface area of the dryer, a much greater expenditure of heat per kilogram of niaterial to be dried. For these reasons a compromise in which the sheet passes through a number of parallel paths of at least om. height, eleven in the case of the apparatus of Fig. 4, with a judicious distribution of the means for heating (introduction, circulation and extraction of the drying fluid) is preferred. However, the invention also includes arrangements for drying in fewer, but longer, unguided lengths. The dryer of Fig. 5 comprises drying apparatus consisting of batteries of lamps emitting infra-red rays, but this is not the only possible method of heating. It is also possible to employ black surfaces internally heated by liquids or other fluids, for example at from 150 C. to 200 C., and also emitting infra-red rays in suiicient quantity, or high pressure-steam radiators, or dielectric devices, or combined apparatus such as apparatus of the latter type for rapidly creating the required temperature combined with heating means of the type emitting infra-red rays for maintaining the temperature.

Fig. 5 shows diagrammatioally the drying chamber 35 having a slot Sli for the admission of the filaments, and an outlet slot 35. The dryer comprises six guide rollers at the top and eleven at the bottom. The rollers are numbered consecutively from 3l' to 53. There are therefore six rising bands and `uve descending bands on the input and output sides of the rollers 38, 4i, 44, 41, 59. Eleven batteries, of lamps 5cl-til emitting infra-red rays are provided, each battery comprising, for example, forty lamps vmaking a total of 44u lamps of from 3Go w. to 35o w. These batteries heat the filaments and assist the evaporation of the water. Within the chamber is situated an air-injection chamber 55, while ducts for the extraction of rnoist numbered consecutively from S5 to lli, are disposed bw tween the batteries of lamps 553, 55, 5l, 53, 59, te, 6i, 52, 63 and Se on the opposite faces of the rising and descending bands. The extraction thus effected sets up a circulation of air along the rising and descending bands of the lament sheet to be dried. It is possible to use a substantial part of the heat extracted from the hot moist air to pre-heat the fresh air fed into the chamber 35. The dryer of Fig. 5 dries the sheet which initially contains from to 200% of water calculated on the dry cellulose basis, to a content of 11% at the most, the'tinle required for passing through the dryer amounting to a fraction of a minute. For example, if the speed of the filament at admission is 163 meters per minute and the total distance through which it passes is 20 meters, the drying takes l2 seconds.

ln order to reduce the area of contact between the sheet and the rollers, the circumference of each roller may be provided with grooves, for example extending parallel with the axis of rotation. A partial section of a suitable 7 grooved roller is shown in Fig. 6, grooves 1i, 12, 7S, etc. being disposed round the whole circumference of the roller.

During drying, the sheet undergoes contraction in length which varies from instant to instant in accordance with a definite law regarding which little is known at present. It is advantageous to adjust the speeds of the rollers so as to allow for this contraction. In a particular embodiment, the roller 3.' can be driven at a fixed speed equal, for example, to that of the squeeze rollers 30, 3l and the roller 53 can be driven at a speed which is lower by a few per cent., for example by 5% (the actual figure is determined by the total contraction on drying), than the speed of the roller 3l. The intermediate rollers are mounted on their shafts by ball bearings, roller bearings, needle bearings, or the like, and the shafts are non-positively driven. at a speed substantially equal to that at which the intermediate rollers 38-52 would rotate if their linear speed were equal to that of the output roller (U. S. Patent No. 2,529,281). In passing over the rollers Ext-52, the filament sheet imparts thereto the little extra speed required by causing the rollers to rotate freely on the bearings. This rotation only exerts a negligible force on the sheet, and the result is that the rollers Stv- 52 adapt their speeds to values intermediate of those cf the rollers 3'! and E3. It is thus possible to control the contraction of the iilainents (depending upon the purpose for which it is to be used) by reduction in the relative speeds of the rollers in the dryer. The filaments leaving the dryer in sheet form can then be suitably wound, for example by means of the device described in British patent specification No. 602,001.

According to an important embodiment of this invention, it has been found that the efficacy of the liquid treatment in the aforesaid process can be considerably improved if successive local areas of turbulence are set up in the treatment liquid in contact with the filaments.

Conveniently, the bundles are caused to travel in individual shallow troughs in which the treatment solution circulates in the same direction as the filaments, said troughs being provided at several points along their length with transverse barriers to stream-line new disposed below the filaments. Such barriers may take the form of vertical or inclined baffles or of channels or depressions in the bottom and/or side wall of each trough spaced at suitable intervals. Alternativoly, spaced projections may be employed.

The aforesaid embodiments of this invention are illustrated by way of example in Figs. 7 to 13 of the drawings.

Referring to Figs. '7 and 8 each trough 8i! is provided at one end with a treatment liquid inlet as at 8i, an outlet (not shown) being similarly provided at the other end. Supporting means for the trough are shown at 32. The bottom of the trough is impressed to form a series of spaced projections or barriers 83 which extend across the width of the trough (Fig. 8). The filaments Y travelling in the direction indicated in Fig. '7 pass immediately above the tops of the barriers t3 and carry treatment liquid along. Eddies or local areas of turbulence are formed on the upstream side and, to a lesser extent, on the downstream side of each barrier 83 thereby to enhance the rate of penetration of the liquid into the filaments at these points.

In the modification shown in Figs. 9 and l0,

S the baffle members 84 have the form of U-shaped members comprising wires projecting from the walls of the trough, the baiile members being located in recesses as at 35. In Fig. 11, the baffle members 81 have the form of inclined bale plates.

In the form of Figs. 12 and 13, the member 88 is provided along its length with a series of inlet pipes 89 for treatment liquid which pipes are located in a side wall of the trough.

The process and apparatus according to the invention permits the carbon disulphide liberated during the washing to be readily recovered and permits the concentration of the noxious gases to be reduced below the toleration limit without excessive ventilation of the rooms in which the spinning and the after-treatments take place. rlhus, hydraulically sealed fluid-tight heads may be fitted on the vats for the purpose of trapping the gases and in particular recovering the carbon disulphide therefrom, for example by condensation with substantial economy of heat and energy of ventilation.

The present invention renders possible the production at low or medium speeds or at speeds which may reach 150 meters or more per minute of viscose rayon filaments having very uniform properties of strength and of aflinity for dyes, with serimetrc values which depend upon the degree of stretching imparted after the coagulation, and the conditions of preparation and spinning. When normal coagulating baths of the Muller type are employed and a relatively low draft, for example from 20% to 30%, is applied, it is possible to obtain filaments having a tenacity of 2 g. per denier or more with an elongation of at least 20%. When a higher draft is applied, for example one of it is possible to obtain filaments with a tenacity of 3.5 g. per denier or more, with an elongation of from 12% to 15% and with an excellent knot strength (65% of normal tenacity). The latter filaments are particularly useful in the manufacture of cord yarns for the reinforcement of pneumatic tires, it being possible to obtain therefrom cord yarns of normal oonstruction having an excellent resistance to fatigue and giving very hard-wearing tires.

Thus, cord yarns comprising two plies of 1100 denier with 480 filaments, first twist 520 turns Z, second twist 480 turns S, per meter, have in the dry state a tenacity of 3.8 g. per denier, the elongation at break being 11% and the elongation under half-load 5.5%. It is also possible to apply the invention advantageously to the manufacture of viscose bundles comprising 10,000 or more filaments, such bundles being intended for the direct manufacture of staple fiber yarns by continuous drawing until breakage of the lilaments, and for other purposes. The method and apparatus of this invention may conveniently be applied to the production of yarns by the process of British Patent 650,896 whereby yarns having a tenacity of more than 4.8 g. pei denier can be obtained. The simplicity of the apparatus of this invention allows a substantial economy in cost of a treated yarn owing to reduced maintenance costs even at high ruiming speeds.

Although an arrangement for drawing by means of rollers in a. hot aqueous medium has been described, any other suitable method and arrangement can also be employed to effect the drawing down of the filaments. For example, the spinning and drawing down of the filaments may take place in a single bath of sufoient length.

We claim:

1. An apparatus for the treatment of a plurality of parallel bundles of regenerated cellulose filaments, which comprises a plurality of liquid treating stages, each treating stage comprising a set of parallel shallow troughs having solid liquidretaining bottoms, side Walls and open ends, the sets of troughs of successive treating stages being arranged in line, pairs of squeeze rollers between successive treating stages and at the end of the last treating stage in the line, the nips of said squeeze rollers lying in a plane extending parallel to and above the bottoms of said troughs and below the tops of the side Walls thereof whereby said bundles extend in parallel straight lines through the troughs and the nips of the pairs of squeeze rollers from one end to the other of the liquid treating stages, means for feeding parallel bundles of regenerated cellulose lament through the said parallel series of troughs and through the nips of said squeeze rollers, means for passing treating liquid to the leading end of each trough with respect to the direction of feed of the bundles to be drawn along with the bundle. and means for collecting liquid from the trailing end of each trough.

2. An apparatus, as set forth in claim l, in which said troughs comprise trays of sheet material corrugated to form parallel troughs and side Walls.

3. An apparatus, as set forth in claim 1, in

which said troughs are so disposed that said plane extends at a slight rising angle with the horizontal.

4. An apparatus, as set forth in claim 1, in which transverse bailles are disposed in each trough to set up local areas of turbulence in liquid flowing from one end to the other of said troughs. 5. An apparatus, as set forth in claim 2, in which transverse bailles are disposed in each trough to set up local areas of turbulence in liquid flowing from one end to the other of said troughs.

HERlVIANN KARLEN. EUGENE COLOMBU.

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